Method and apparatus for setting cutting tools in machine tools

ABSTRACT

A machine tool has front and rear cross slides with tool locating means thereon and a turret with a tool locating datum surface thereon. The cutting tools for the machine tool are preset prior to their being mounted on the turret and cross slides. The tools are preset by using apparatus which includes a first jig operable to preset tools for use on both the front and rear cross slides prior to positioning said tools on said cross slides and a second jig for presetting tools for use on said turret. Both jigs include a reference surface simulating the datum plane so that tools preset on said jigs are easily and quickly positionable on the machine tool with reference to the datum plane. The apparatus further includes a datum surface transfer arm having a transfer surface adapted to lie on the datum surface, and means for mounting said transfer arm on the turret so that the transfer arm is operable to facilitate positioning the tools on the cross slide.

United States Patent Harkness 3,789,509 Feb. 5, 1974 [75] Inventor:Leslie Harkness, Halifax, England [73] Assignee: Warner Swasey AsquithLimited,

Halifax, England [22] Filed: Sept. 27, 1971 [21] Appl. No.: 183,949

Related US. Application Data [62] Division of Ser. No. 752,604, Aug. 14,1968, Pat. No.

[52] US. Cl. 33/185 R, 33/172 B, 82/1 C [51] Int. Cl. 827g 23/00 [58]Field of Search 33/185 R, 181 R, 189 R, 172 B;

[56] References Cited UNITED STATES PATENTS 1,877,654 9/1932 Flink et a]108/129 3,292,267 12/1966 Wilterdink et al. 33/185 R 3,417,478 12/1968.leanneret 3,555,690 l/l97l Matthey 33/185 R Primary Examiner-William D.Martin, Jr.

[57] ABSTRACT face simulating the datum plane so that tools preset onsaid jigs are easily and quickly positionable on the machine tool withreference to the datum plane. The apparatus further includes a datumsurface transfer arm having a transfer surface adapted to lie on thedatum surface, and means for mounting said transfer arm on the turret sothat the transferarm is operable to facilitate positioning the tools onthe cross slide.

4 Claims, 11 Drawing Figures Patented Feb. 5, 1974 8 Sheets-Sheet 1 FIG.2.

Patented Feb. 5, 1 974 8 Sheets-Sheet 2 Patented Feb. 5, 1974 3,789,509

8 Sheets-Sheet :5

Patented Feb. 5, 1974 8 Sheets-Sheet 1 Patented Feb. 5, 1974 3,789,509

8 Sheets-Sheet 5 Patented Feb. 5, 1974 8 Sheets-Sheet 6 Patented Feb. 5,1974 8 Sheets-Sheet 7 Patented Feb. 5, 1974 a Sheets-Sheet 6 METHOD ANDAPPARATUS FOR SETTING CUTTING TOOLS IN MACHINE TOOLS This is adivisional application of Ser. No. 752,604, filed Aug. 14, 1968, nowU.S. Pat. No. 3,625,097, issued Dec. 7, 1971,.

The present invention relates to a method and apparatus for use inpresetting tools prior to their being mounted in a machine tool.

It has been recognized that the productivity of a machine tool, such asa lathe, could be improved by presetting the cutting tools in theirtoolholder before fitting the toolholder in the machine tool. This isbecause, the presetting of the tools for one tool set-up can be donewhile the machine tool is in operation using a previous tool set-up.

On object of the present invention is to provide a method of presettingcutting tools for subsequent use in a machine tool and which is verysimple to carry out and enables alterations in the workpiece location tobe readily accommodated.

Another object of the present invention is to provide for new and novelapparatus for presetting cutting tools for use in a machine tool havinga cross slide and a turret and wherein the apparatus includes a transfermeans operable to facilitate positioning of the preset tools in thecross slide and the turret in a desired relationship relative to eachother and to the workpiece.

Another object of the present invention is to provide a new and improvedmethod of locating tools for use in a machine tool having a cross slideand a turret wherein a datum surface is provided on the turret, and theplane of location of the datum surface is transferred to the crossslides by a transfer means which may be mounted in the turret and extendtoward the cross slides.

A further object of the present invention is the provision of a new andimproved method for presetting tooling which includes the steps oflocating a datum plane in relation to a workpiece locating surface inthe machine tool and against which the workpiece abuts and presettingthe tooling on a fixture separate from the machine tool having areference surface simulating the datum plane by reference to thereference surface.

A further object of the present invention is the provision of a new andimproved method and apparatus for presetting tooling, as noted above,wherein the end location surfaces of chuck jaws against which theworkpiece abuts are used as the workpiece locating surface from whichthe datum plane is located.

The advantage of using a datum plane measured from a workpiece abuttingsurface, as noted above, is that if the surface is altered (e. g. bygrinding hard jaws or turning soft jaws) then a fresh datum plane can beestablished and the tool carrier on the turret moved up to this plane.All the tools carried by the tool carrier will then be in the correctposition without further adjustment.

The invention also comprehends apparatus for carrying out the aforesaidmethod, and in particular it includes within its scope presetting jigs.

According to this aspect of the invention a jig for presetting toolingready for subsequent use on a machine tool comprises location supportmeans for a toolholder, and reference surfaces fixed relatively to saidlocation support means to provide for positioning the operative edge ofa tool in three planes on said location support means.

The jig preferably simulates at least part of a tool carrier (thisfacilitating a visual appreciation of the tooling set-up) and where thetooling is for use on a lathe, it may simulate a tool carrier formounting on the lathe cross-slide. In that case, one of the referencesurfaces may be so positioned relatively to the location support meansthat is bears a known relationship to the axis about which the workpiecerotates on the machine.

Also in the case of a jig for presetting cross slide tooling, there maybe a side plate providing an end location plane from which axialdisplacement of tooling can be located. Preferably there are two suchside plates, to provide end location planes for tooling to be mounted infront and rear cross slides respectively.

These and other objects of the invention will become apparent from thefollowing description of a preferred embodiment of the invention takenin conjunction with the accompanying drawings and in which:

FIG. 1 is a diagrammatic perspective view of a chucking automatic latheshowing the principal components and their permitted movements;

FIG. 2 is a perspective view from above of a presetting jig for crossslide tools, with two tools in position;

FIG. 3 is a plan view of the jig shown in FIG. 2, but with three toolsin position;

FIG. 4 is a view in the direction of the arrow IV in FIG. 3;

FIG. 5 is a vertical section through a height gauge for use with the jigshown in FIGS. 2, 3 and 4;

FIG. 6 is a plan view of a jig for turret-mounted tools;

FIGS. 7A and 7B combined are a side view of the jig shown in FIG. 6;.

FIG. 8 is a detail sectional view on the line VIII-VIII in FIG. 7;

FIG. 9 is a front view of part of a chucking automatic lathe showing themethod of setting tools in the lathe; and

FIG. 10 is a detail end view of a transfer arm.

The present invention provides a new and improved method and apparatusfor presetting cutting tools for use in a machine tool. Although thepresent apparatus and method associated therewith could be applied tovarious machine tools it is herein disclosed for use with a turret lathehaving front and rear cross slides.

The illustrated embodiment provides a sophisticated yet easily operablesystem for presetting tools for use on the turret and the cross slidesof a machine tool. The apparatus includes a pair of jigs, one operableto facilitate presetting tools relative to their respective toolholdersor tool carriers for use in the turret and the other operable tofacilitate presetting tools relative to their toolholders for use inboth the front and rear cross slides. After the tools are presetrelative to their respective toolholders they are transfered to themachine tool for mounting thereon. Prior to mounting the tools on themachine tool a datum plane is established on the turret. The crossslides contain tool locating means which are then located in apredetermined position relative to the datum plane on the turret bymeans of a transfer arm. The transfer arm is mounted on the datumsurface of the turret and the tool locating means are then brought intoengagement with the transfer arm. After the tool locating means arepositioned the transfer arm is removed from the turret and the presettools are placed on the turret and the cross slides.

For purposes of illustration and description the method of presettingtooling and apparatus for use in presetting tooling in accordance withthe present invention is described as applied to an automatic chuckinglathe. The lathe, illustrated in FIG. 1, comprises a box column ofsubstantial construction built on a bed 12. The column 10 houses theworkpiece driving mechanism (not shown) and provides bearings for aspindle 14, on one end of which is mounted a chuck 16. The chuck may beof any known type with hardened or soft jaws according to the kind ofworkpiece which is to be gripped.

A support bracket 18 fixed to the column 10 has upwardly and inwardlyinclined cross-slides 20 and 22, on which can be mounted cross-slidetool carriers (not shown in FIG. 1). The cross-slide carriers can eachmove along their respective slides as indicated by the arrows C, C tofeed their cutting tools into the workpiece. It will be observed thatthe cross-slide tools have no axial traverse, so that they can only beused for such operations as feeding, recessing, chamfering andparting-off.

A forged steel turret support bar 24 extends through.

the column 10 parallel with and above the spindle l4, and projects oneach side of the column. At the chuck side of the column, the bar 24 isformed with a pentagon turret 26 near to its end, this turret having adovetail recess in each of its five faces to receive a turret toolcarrier.

Thebar 24 is mounted and controlled so that it can reciprocate axiallyas indicated by the arrow D, and index about its own longitudinal axis,as indicated by the arrow E, in 72 steps to bring each of its faces inturn into an operative position on the underside. The bar indexes one ormore steps between two successive reciprocations. On the opposite end ofthe bar 24 to the turret 26, there is a control cage 28 for mountingspeed and feed control dogs (not shown), and other lathe controls arelocated in this area.

It will be observed that cutting tools fixed on the turret 26 will havea purely axial traverse so that they can be used for ordinary turning,drilling, boring, reaming and tapping operations, but not facing,recessing, parting-off, or taper turning. However, it is possible to fiton the turret a special toolholder which incorporates a smallcross-slide and to arrange for inward movement of one of the cross-slidecarriers equipped with a pusher which pushes the cutting tool across thesmall cross-slide on the turret to enable a boring bar to perform arecessing operation, or to enable a facing or parting tool on the turretto have its required lateral movement. Furthermore, the specialtoolholder can be provided with a roller following a cam fixed to one ofthe cross-slides, so that the tool on the turret turns (for example) ataper on the workpiece.

It will be appreciated that only the basic features of the lathe havebeen set out above. One essential feature in relation to thetool-setting procedure is that the cross-slide carriers and the turretbar have fixed working strokes and that the in-feed strokes always endagainst fixed stops. Thus, the size of the component produced on thelathe is determined solely by the loca tion of the cutting edges of thetools relatively to the cross-slide carriers or the turret bar as thecase may be. The setting apparatus procedure is intended to produce thiscorrect location.

Cross-slide Tool-setting Jig.

A jig as illustrated in FIGS. 2, 3 and 4 is provided for setting thecutting tools for use in the cross-slides of the lathe. This jig isseparate from the late so that it can be used to pre-set tools while thelathe itself is in use on another job, and in some workshop conditionsit may be possible to use a single jig to service several lathes.

The jig has a substantial hardened steel bed 40 which is formed with adovetail portion 42 in exact replica of the dovetail portion on thecross-slide tool carriers, so that a toolholder can be fitted on to thebed 40 of the jig for tool setting purposes. Two toolholders 44 and 46are shown in position on the bed 40 of the jig in FIG. 2 and three inFIG. 3. The toolholders are of conventional construction, with dovetailrecesses in their undersides which enable them to be fitted on to thedovetails portions of the cross-slide tool carriers. When thetoolholders are placed on the setting jig, they are firmly locatedlongitudinally by the dovetail portion 42, but they can slide laterallyon this portion as they could on the lathe tool carrier. In thisrespect, the bed of the jig simulates the actual tool carrier on thelathe, and it is a feature of this invention that the setting jigs dothus simulate tool carriers and so make it easier for the setter tovisualize the effect of his setting procedure.

Two toolholders 44 and 46 are illustrated in FIG. 2, but it will beappreciated that this is only by way of illustration and that the jigcould be used to get a single tool or more than two tools according tothe tooling re-. quirements of the cross-slide. The toolholders are, ofcourse, equipped with means for clamping to the crossslide tool carrier,and these means can be used on the setting jig if necessary.

The top surface 48 of the bed 40 provides one of the reference surfacesof the jig for tool setting purposes, and it is therefore important thatthis surface should be flat and have a definite spacial relationship tothe dovetail portion 42. A vertical rear wall 50 stands upright from thebed 40, and the front face 52 of this wall forms a second referencesurface on the jig for toolsetting purposes. It is important therforethat this face 52 should be flat and at right angles to the top surface48 of the bed. The front face 52 is spaced from the dovetail portion 42of the bed by a distance less by a known amount, then the distancebetween the vertical plane passing through the axis of rotation of theworkpiece spindle 14 of the lathe and the dovetails of the crossslidetool carriers when the latter are pressed against their stops at the endof their in-feed movement. The radius of the portion of the workpiecewhich will be machined by a tool such as 41, will be equal to theperpendicular distance between the front face 52 and the cutting edge ofthe tool plus the known amount by which the face 52 is offset from theplane equivalent to the plane passing through the axis of rotation ofthe workpiece.

Two horizontal slots 54 and 56 are formed in the rear wall 50 each ofwhich is adapted to receive a diameter gauge 58. The latter has a stock60 with a flat front face 62 for engagement with the face 52 of the rearwall 50 of the jig, and a sliding scale rule 64 which can project fromthe stock through one of the slots 54 and 56 towards a tool mounted in atoolholder on the jig. The scale rule is divided to a suitable scale,but in addition there is a dial gauge 66 which is coupled to the rule sothat very accurate readings are possible. The scale is calibrated sothat it reads the radius to be turned by the tool. Of course, the scalecould be calibrated to read off diameters rather than the radii ifdesired. The stock 60 of the scale is provided with a spring clip 61,whereby it is retained in the slot 54 or 56.

On the particular lathe for which the pre-setting has been designed, thetool carriers on the front and rear cross-slides are of the same size.This enables a toolholder to be used on either carrier, but if the sametoolholder is to be capable of use on either slide, then the cuttingtools must be set at different heights on the jig, because in use, thoseon the rear cross-slide will be inverted. Therefore, if a tool is to beset for use on the rear cross-slide of the lathe, it will need to belower on its carrier than if it were to be mounted on the frontcross-slide. For this reason there are two slots 54, 56 in the rear wall50, so that the diameter gauge 58 can be mounted at different heights,the lower slot 56 corresponding to a tool for the rear cross-slide andthe upper slot 54 corresponding to a tool for the front cross-slide.

The tool height relative. to the axis of rotation of the workpiece canbe adjusted by conventional means applied below the tool in thetoolholder 44 or 46. Normally, the cutting dge of the tool should beabout level with the axis of the workpiece. This height can be gauged bymeasuring from the reference surface provided by the top surface 48 ofthe bed 40, and a special invertible height gauge 68 illustrated in FIG.5 is used for this purpose. This height gauge will be describedseparately. It will suffice to say that the height gauge can be used toset tools to the correct height for either the front or rearcross-slide.

Side plates 70 and 72 are provided one at each side of the bed 40. Eachside plate is pivoted on a lower screw clamp 74, and has two slots 76and 78 which engage on screw clamps 80 and 82 respectively when the sideplate is raised to its operative position as shown in FIG. 4. When allthree clamps 74, 80 and 82 appertaining to one side plate are tightened,the plate is held rigid with the bed and rear wall. One of the sideplates must be lowered each time toolholders are fitted on to or removedfrom the dovetail portion 42.

The outside faces 84, 86 of the side plates provide third referencesurfaces for the jig to enable the jig to be used to pre-set the axialposition of the toolholders on the tool carrier. These outside surfaceseach represent a datum plane on the lathe lateral of the workpiece. Thisdatum plane bears a constant axial relationship to the workpiece whenthe latter is gripped in the lathe chuck and therefore it is possible toset the axial positions of tools to produce machined surfaces in thecorrect axial positions by reference to this datum plane.

Each toolholder for use on the cross-slides is formed with a lateralscrewed hole 88, and an axial location peg 90 of hardened steel has ascrew-threaded shank 92 for engagement in the hole 88. When thetoolholder has been correctly positioned axially on the jig, thelocation peg can be adjusted in the toolholder until the peg touches theappropriate inside surface 85 or 87 of the side walls 70 and 72respectively. This provides a means of transferring the axial locationof a toolholder on the lathe cross-slide as will be described hereinbelow.

Two side plates 70, 72 are provided because the surfaces 84 and 85 onthe plate 70 can be used to set tools for mounting in the frontcross-slide, whereas the surfaces 86 and 87 on the plate 72 can be usedto set tools for mounting in the rear cross-slide.

A length gauge 94 is provided, and this gauge is similar in constructionwith the diameter gauge 58. The length gauge can be clipped into a slot96 in the side plate or a corresponding slot at a lower level(appropriate to rear cross-slide tooling) in the plate 72, and when inthis position it can be used to read the lateral position of a cuttingtool on the jig as shown in FIG. 2.

It will be observed that both the diameter gauge 58 and the length"gauge 94 can be read at the same time, and this is an important featureof the invention. In fact, the height gauge 68 can also be brought intooperation at the same time if desired, so that all three locationreadings can be made simultaneously.

Referring to FIG. 3, in which there are three toolholders 44, 45 and 46,it will be observed that the toolholder 46 (also shown in FIG. 2) has achamfering tool 43, while the extra toolholder 45 has a back chamfertool 47.

Now the jig provided by the invention lends itself to the setting ofchamfer tools. As shown in FIG. 3, the length gauge 94 is set to thelength of the end face which is to be chamfered, and the diameter gaugeis set to the radius at the bottom of the chamfer less the width of thelength rule. The rules of these two gauges abut each other as shown inFIG. 3. The cutting edge of the tool 43 is then pushed to the corner ofthe length rule. The chamfer tool is then correctly set.

It will be observed that there are recesses 49 in the scale of thelength gauge 94. The axial position of the cutting edge of a back facingtool can be measured against the face 99 of one of these recesses. Thelength of the front of the gauge between the end and the recess isknown, so that this can be subtracted from the length measured on thescale to give the setting of the back facing tool. In FIG. 3, the gauges94 and 58 are shown being used to measure the setting of a backchamfering tool 47.

Height Gauge.

Referring now to FIG. 5, the height gauge 68 comprises an open endedcylindrical column 100, with a dial gauge 102 in its top end and a dialgauge 104 in its lower end. These dial gauges are arranged with theirfaces directed outwardly, and their respective plungers 106 and 108directed inwardly the gauges are held in position by screws 110.

An internal annular flange 112 provides a pivot mounting for a finger114, which projects through a slot in the cylindrical wall of the column100.

The plungers 106 and 108 are loaded inwardly by compression springs 107and 109 respectively. A restricting screw 116 is fixed in the flange112, and projects into a hole 117 in the tail 118 of the finger 1 14.The spring 109 is stronger than the spring 107 causing the tail 118 ofthe flange 112 to be normally pressed on to the underside of the pointedend of the screw 116. The screw 1 16 serves to prevent large deflectionsof the plungers 106 and 108, which could damage the dials 102 and 104,but permits small displacements such as the dials are intended torecord. It will be observed that the finger 114 is further from thelower end of the column than it is from the upper end. The arrangementis such that the underside of the finger is at the same level as theplane corresponding to the correct height setting for a cutting tool foruse on the front cross-slide when the gauge 68 is standing upright onthe surface 48 of the bed 40 and the finger 114 is horizontal, whereaswhen the gauge 68 is inverted and stood on the surface 48, the undersideof its finger 114 (previously the top side) is at the correct centerheight for tools to be used on the rear cross slide.

The plungers 106 and 108 are of unequal length, and engage on oppositesides of the tail 118. The dials 102 and 104 are both set at zero withthe finger 114 horizontal In use, if a cutting tool is being set for usein the front cross-slide of the lathe, the gauge 68 is placed in anupright position on the bed 40 and the finger 114 is brought intoengagement with the cutting edge of the tool. As soon as the tool isabove the correct center height, the finger 114 is tilted upwards, thetail 118 is lowered and the plunger 106 extends to produce a reading onthe dial 102. In this manner it is possible to set the height of thetool accurately. When the tool is accurately set in the toolholder theclamping screws 120 are tightened to lock the tool in a set position.

If the cutting tool is for use in 'the rear cross-slide of the lathe,the same height setting procedure is followed, but the gauge 58 is usedin the inverted position and the readingis obtained on the dial 104.

Turret Tool-setting Jig.

The pentagon turret 26 on the lathe (FIG. 1) provides for mounting fivetool carriers each of which can carry drills, boring bars, taps, dies,length cutting tools or cross-cut tool attachments. It will beappreciated, that five carriers represents the maximum tool loading ofthe turret and that for the machining of particular components it maynot be necessary to use all five carriers.

A turret tool-setting jig is provided separate from the lathe, and aswith the cross-slide setting jig, there may be one turret jig for eachlathe, or a single turret jig may serve several lathes. Theturret-setting jig is illustrated in FIGS. 6 and 7, and comprisesbasically a block 140 which is of substantially the same shape as thetool carriers used on the turret of the lathe.

The block is formed with accurately positioned holes 142, 144, 146 and148 in the same positions as toolholder holes in the carriers on thelathe. Of these, the holes 142 is positioned so that is simulates acarrier hole which is co-axial with the lathe spindle 14 when thatcarrier is brought to the operative position by indexing of the turret.On the tool carrier, this hole (corresponding to the hole 142) is usedfor drills and like tools which have to be set coaxial with theworkpiece. The other three holes of the carrier (simulated by the holes144, 146 and 148 in the jig block) are intended to receive toolholderssuch as that shown in FIGS. 6 and 7, having a cylindrical shank 150which fits into the hole in the carrier and a body 152 in which theactual cutting tool such as 154 is received in a slot or recess 156 andcan be locked there-in by screws (not shown).

The shank of each toolholder is formed with two diametrically opposedlongitudinal grooves 160, and a part or location collar 162 is providedfor each tool, the collar or part fitting loosely around the shank 150,but having a detent 164 and an opposed setscrew 166 for engagement inthe grooves 160. The setscrew 166 is not diametrically opposed to thedetent 164 on the collar, but is offset to one side of the diametricallyopposed position. By tightening the setscrew 166, the collar can belocked on to the toolholder shank in any preselected longitudinalposition, and the offsetting of the setscrew 166 ensures correct angularlocation of the collar on the shank. A lug 168 is provided on the collar162, and there is a hole 170 in this lug to receive a fixed location pegon the tool carrier. Each of the holes 144, 146, 148 has an associatedpeg 174, 176 and 178 which have the same disposition on the block as thelocation pegs on the tool carrier. The appropriate peg, 174, 176 or 178can be received in the hole 170 of a collar 162 and there are opposedsetscrews 180 in the lug 168, which can be tightened on to the peg tolocate the collar and thereby orientate a toolholder gripped by thecollar relatively to the hole in which the shank of the toolholder isreceived.

The adjustment of the toolholder about the axis of its own shank enablesits tool to be set at the correct center height for cutting purposes.The term height is used in this respect for convenience althoughstrictly speaking no vertical dimension is involved with a tool set onthe turret. In addi-tion to the holes simulating the toolholder holes inthe tool carrier, there is an additional hole with its longitudinal axisa predetermined distance from the axis of the hole 142.

The block 140 is placed on a bed (not shown) which incorporates amanually operable lifting device having ifting elements projectingupwards into each of the holes 144, 145, 146, and 148 on which the lowerend of the toolholder shanks rest. Thus, toolholders placed in the block140 can be raised or lowered by operation of the lifting device, and allthe toolholders will be moved through the same vertical distancewhenever there is vertical adjustment.

It will be appreciated that the top surface 149 of the block 140simulates a vertical surface on the actual tool carrier when the latteris in position on the lathe turret, and therefore the height of thecutting tool above the top of the block 140 represents an axial settingof the tool on the lathe. This setting has to be such that for a givendatum position of the face of the carrier (the setting of which will bedescribed later) the cutting tools in that carrier will arrive at thecorrect axial position relative to the chuck jaws to produce machinedsurfaces of the correct length when the turret bar 24 arrives at the endof its in-feed.

Locking means are associated with each of the holes 142, 144, 145, 146and 148 to enable a shank to be locked in a pre-set position on theblock 140. These locking means are of a conventional nature and need notbe described in detail. A long screw 182 extending through from a partof the block has a pressure pad at its rear end for engagement with theshank of a toolholder in the hole 145. Similarly, a screw 184 extendsfrom one side of the block to apply pressure on the shank in the hole142. Each of the holes 144, 146 and 148 is equipped with a double-wedgeoperated clamp 190, the wedge being operable by a screw 192. Thesescrews 182, 184 and 192 all have hand knobs 186, 188 and 193respectively so that light pressure can be applied to their respectivetoolholder shanks, and the locking and unlocking of toolholders in theholes 142, 144, 145, 146 and 148 is very easy.

A bracket 194 is bolted to the rear of the block 140, and a cylindricalcolumn 196 stands vertically upwards from this bracket. Through thecolumn 196 there extends a spindle 198 which can turn about its ownlongitudinal exis, but which is locked against endwise movement. An arm200 is fastened at one end to the top end of the spindle 198, this armextending horizontally from the spindle.

The arm 200 can be turned about the spindle axis, and locked in anyselected angular position by a clamping member 202 having a screwed part204 on which there engages a knob 206 (see FIG. 8). This enables the arm200 to be brought over any part of the block 140, or moved clear of theblock to allow toolholders to be fitted.

A length gauge 208 is provided, this gauge being of the same type as thegauge 58 previously described, and it fits in an elongated slot 210 inthe arm 200, and extends downwardly therethrough as illustrated in FIG.7. The perpendicular distance between the topside of the arm 200 and thetop surface of the block 140 is determined and the scale of the gauge208 is so arranged that the gauge reads the extension of a tool from theface of the block 140, and, as will be described later, this gives thefinished length dimension of the front of the workpiece to be machinedby that tool.

A special radius gauge 212 is also provided for use with the turret jig.This gauge has a stock 214 with a sliding calibrated scale 216, and inthese respects it resembles the gauges 58 and 208. However, the stock isrotatably mounted on a head 217, from which a cylindrical shank 218extends downwardly, and this shank fits in the hole 142 (which it willbe remembered is the hole simulating the hole coaxial with theworkpiece). A screw 219 is provided for locking the stock to the head217.

The shank 218 can be locked axially by the screw 184, which carries anon-rotatable insert 185, this insert having opposed flats to produce akey which engages on the side walls of a longitudinal recess 187 in theshank 218. The end of the screw 184 is pressed against the bottom of therecess 187 when the screw 184 is rotated. Furthermore, the shank isoffset relatively to the stock, so that when the shank is located in thehole 142 the calibrated edge 220 of the scale passes through the axialcenter line which is equivalent to the axial center line of theworkpiece on the lathe.

Another feature of the radius" gauge is that the end face 222 of itsscale passes through the axial center line equivalent to the axialcenter line of the workpiece when the scale is reading zero, but the endface 222 is at right angles to the calibrated edge of the scale.Consequently, when the scale is reading zero, the corner of the scale atthe junction of its calibrated edge and its end face 222 represents theaxis of rotation of the workpiece. This axis is also that about whichthe stock is rotatable on the head 217.

It will be appreciated therefore that when the scale 216 is extended totouch the tip of a cutting tool mounted in any one of the holes 144,146, 148, it measures directly from the said corner the radius whichwould be machined by a tool set in that position.

A further accessory for use on the turret jig is a tool alignment gauge224. This simply consists of a magnetic block 226 having a flat insidesurface 228 which locates on the side wall of a toolholder body 152, anda rod 230 slidable but not rotatable in a longitudinal hole in the block226 with a hardened steel peg 232 slidable in a hole at the front end ofthe rod at right angles to the permissible movement of the rod. A screw234 is provided for locking the peg 232 in any selected extendedposition.

Setting a Turning Tool on the Turret Jig.

If a turning tool such as 154 is to be used on a carrier on the latheturret, it will be preset on the jig which has just been described. Thetool will be held in a toolholder, and the setter will select into whichof the holes 144, 146 and 148 the toolholder is to be fitted dependingupon thediameter of the workpiece which is to be turned by that tool andany other tools which are to be used on the same tool carrier. In anyevent, the procedure for tool setting is the same whichever of the holesis selected.

The setter will also know what will be the axial position of the datumface of the tool carrier on the lathe as this will have been determinedby planning to ensure the minimum tool projection from the carrier. Thisaxial position will be represented by the top surface of the block 140.

The toolholder is mounted in the selected hole and lightly clamped. Thenthe tool alignment gauge 224 is placed on the side of the toolholderbody (FIG. 6) and the height peg 232 is set so that it just touches thetop of the tool cutting edge, and locked by the screw 234. The rod 230of the alignment gauge is then slide forwardly to a position where itspeg is aligned with the projecting part of the scale 216 (which at thestage will be retracted to near the zero setting). The toolholder isthen released and turned until the peg 232 just touches the calibratededge of the scale 216. This procedure ensures that the cutting edge ofthe tool is at the correct center height and at this state, the collar162 is clamped on to the tool shank by the setscrew 166 and the screws180 are brought to bear lightly on the locating peg 176 (see FIG. 6). Atthis stage, the angular relationship of the toolholder to the carrierhas been selected.

Next, the scale 216 of the radius gauge 212 is extended to a somewhatlarger radius than the tool is required to cut, and the rod 230 is slidback in its block 226 until it is near to the Zero end of the scale 216(i.e. the outer extremity of the scale). The stock of the radius gauge212 is then turned on its own axis until the scale touches the heightpeg 232. The gauge 212 can then be locked by tightening the screw 184and the screw 219 and the angular position and height of this guage arethen fixed. The tool is then extended from its holder to push the scale216 until the required radius to be cut by the tool is read on theradius gauge 212, whereupon the tool can be locked in its toolholder,and the active radius of the tool has been selected.

To set the axial portion of the tool, the scale of the I length gauge208 is set above the cutting edge of the tool at a slightly smallerreading than that ultimately required to produce the correct length onthe workpiece. Then the setscrew 166 is slackened and the toolholder israised pushing the scale of the length gauge until the latter registersthe required length. The setscrew 166 is then locked, care being takento assure that the collar 162 remains on the locating peg 176 and inengagement with the face of the block 140. The toolholder is thenproperly preset for use on the lathe. If desired, the radius can againbe checked by the scale 216, so that readings of radius, length andcenter height can be viewed simultaneously.

Pre-setting Boring Bars Boring bars are pre-set on the turret settingjig and the hole is used for this purpose. Since the axis of the boringbar is the same as the workpiece axis, it is not necessary to set thetool height. Consequently, the angular position of the cutter isimmaterial.

Each boring bar has four longitudinal flats spaced at 90 on its shank,and the long screw 182 can be tightened against one of these flats tolock the bar.

The head 217 of the radius gauge 212 has a fixed stop 221, and a peg 223is provided on the stock 214 for engagement with the stop. The stop isso arranged that when it is engaged by the peg 223, the calibrated edgeof the scale 216 is pointed towards the longitudinal axis of the hole145.

In setting a boring bar, the stock of the gauge 212 is brought into thisstop-engaged position and locked by the screw 219. The tool is adjusteduntil, when revolved about the axis of the hole 145, it pushes the scale216 to the required radius. Then the tool is clamped in the boring barand the bar elevated by the lifting mechanism until its cutting edge isat the correct axial position (as measured by the length gauge). Thecutting tool is locked by its locking screw and a collar on the shank ispressed against the top surface of the block 140 and then locked to theshank, the boring bar is then set ready for use in the lathe.

Pre-setting Turret Slide Head Tools.

internal machining operations such as facing, counterboring, grooving,forming and back facing can be performed by a turret slide headattachment. This comprises a metal block having a dovetail projection tofit on one of the sides of the turret in place of one of the toolcarriers previously referred to. This block has a slideway with a slidemember so arranged that it can travelacross the block laterally of thelathe. Generally, the slide member is spring loaded so that it normallyrests at one end of its permitted traverse, and it has one or more holesparallel with the axis of rotation of the workpiece to receive theshanks of cutting tools (which are frequently boring bars).

Such an attachment permits the shank of a toolholder to be offset fromthe axis of rotation of the workpiece, and it also permits the tool tobe moved (say by late operation of the lathe cross-slides) to cut arecess in a bore or to carry out taper turning operations.

Such a tool is placed in the hole 145 and is set for radius and lengthin much the same manner as a boring bar. The shank of the cross-slidetool also has four flats to enable it to be locked at 90 positions.

With this kind of tool, the alignment with the axis of rotation of theworkpiece will affect the radius cut by the tool. Misalignment,therefore, has to be measured and allowance made in the radius setting.For this purpose, a special alignment gauge 240 (FIG. 7 is provided, andthis gauge consists of a magnetic stock 242, a scale 244 fixed to thestock, two fingers 246, 248 slidable on the scale, and a dial 250operative by either of the fingers. Each of the fingers 246, 248 has agauging edge 252, 254, respectively, and these edges lie in the sameplane when at the zero position but the edge 252 faces the column 196whereas the edge 254 faces in the opposite direction.

The shank of the toolholder is turned through 90 from the position atwhich the radius is set, and then the gauge 240 is used to measure thedisplacement of the tool from true alignment. The two fingers 246 and248 are required to provide for tools on either side of the toolholder(i.e., operating as front or rear crossslides) and for forward orreverse rotation of the lathe spindle. When the displacement has beenread on the dial 250, appropriate allowance can be made in the toolradius setting.

Special Adaptation of' the Lathe for Pre-set Tooling Very littlemodification as adaptation of the lathe itself is required and this isan advantage of the invention. A location stop is provided on eachcross-slide, a location transfer arm is provided for use on the turret,and it is necessary to have a set of length gauges. Each of these itemswill now be described in 'turn.

Location Stop FIG. 9 shows a location stop 300 on the front crossslide.It will be understood that there is an identical stop on the rear-slide,so that only the front stop need be described in detail. A bracket 302is fixed onto the side of the tool carrier on the cross-slide by setscrews 304, and this bracket projects above the dovetail portion of thetool carrier. A hardened steel stop screw 306 passes through alignedholes in a bifurcated portion 308 of the bracket 302, there being aknurled nut 310 engaged on the screw 306 in the bifurcated portion.

By turning the nut 310, the projection of the screw stop on the toolcarrier side of the bracket can be adjusted. Thus it is possible to setthis end of the screw stop to any selected datum plane on the lathe.When this position has been selected a toolholder can be removed fromthe cross-slide jig and placed on the tool carrier of the cross-slide,with its location peg engaged against the end of the screw stop 306, andthat tool will then be correctly positioned on the lathe.

Transfer Arm FIG. 10 shows that the transfer arm comprises a twoarrnedmember 320 having a central boss 322 in which there is a screwed hole324. A clamping bolt 326 has a collar 328 with a chamfered side wherebyit can be located in one end of the lowest hole 330 in a tool carrier332 on the lathe turret 26. A knob 334 is provided on the collar end ofthe bolt 326, and the other end is screwed for engagement in the screwedhole 324 of the transfer arm.

The transfer arm can be titted to any of the tool carriers on theturret, and this is done by passing the shank of the bolt 326 throughthe hole, as shown in FIG. 9. When the bolt is tightened, the boss ofthe transfer arm is pulled tight against the face of the tool carrier332. The arms 336 and 338 of the transfer arm then extend in line withthe location stops 300 of the front and rear cross-slides, and these canthen be brought to bear on the arms 336 and 338 so that the locationstops and the front face of the carrier 332 are all in the same plane(herein referred to as the endwise location plane).

The facility for quick alignment of the location stops with the frontface of the turret tool carrier, which is provided by the transfer armis very useful in the setting of the machine and resetting afteradjustment of the workpiece location surfaces.

Length Gauges.

The length gauges are used between the end location surface for theworkpiece (i.e., a face of the chuck jaws 340, such as 342 FIG. 9) andthe front face of the tool carrier 332. A body 344 has a recess at oneend to receive any one of a series of rod length gauges (one of which isshown at 346) to provide large increments of length adjustment, and atthe other end it has a head 348 with provision for slip gauges 350 to beinserted for small length increment adjustment.

Setting the Tooling It is preferable that the tooling be planned so thatthe setter has charts showing which tools are to be fitted in each ofthe five turret and two cross-slide tool carriers. The tool planningshould also establish the distance of the front faces of each turrettool carrier (datum plane) from the end location surface on the chuckjaws at the end of the in-feed of the turret. The five datum planes willbe selected to give the minimum overhang of tools from the carrier.

The setter then moves the turret against the end stop at the limit ofits in-feed and proceeds to set each of the turret carriers to its owndatum plane by the use of the length gauges. At the planning a datumplane will have been selected for the end stop of the cross-slides ofthe lathe, which may or may not be one of the datum planes of the turrettool carriers. One of the turret carriers is set to this special datumplane and the transfer arm is fitted to this carrier and the planetransferred to the end location stop on the cross-slide. The turret toolcarrier which has been used for this purpose can then be set to its owndatum plane.

At the planning stage it is desirable that all the datum planes selectedfor the cross-slide end stops and the turret carriers should be the sameor spaced from each other by distances which are exact multiples of thelarge increment adjustment stops provided by the rods 346 of the lengthgauges. This avoids the necessity for changing the slip gauges 350during a lathe tooling operation. The lathe itself is then ready toreceive the tooling. All tools are present on the appropriate jigs aspreviously described, and then the toolholder with the tools in positionare simply transferred to the lathe and clamped in position in thenormal manner. The turret tools are located by their pegs. The lathe isthen ready for use.

Supposing that fresh chuck jaws have to be fitted on the jaws ground orturned, this will, of course, alter the workpiece end location surfaces.The length gauge is then used to reset the carrier on the turret and thenew datum plane is transferred to the cross slides by the transfer arm,so that operations can recommence. But it will not be necessary to resetany of the tools since they will all maintain their correct locationrelative to the workpiece location.

It will be appreciated that the entire operation of tooling is verysimple besides the saving in time due to the ability to set the toolswhile the lathe is working on a previous job.

In the above example, the lathe described has a turret which isrotatable about an axis parallel with the axis of rotation of theworkpiece. It should be understood however, that the invention could beapplied to a lathe having a turret rotatable about an axis which is notparallel with the workpiece axis by suitable modification of the gaugesused on the turret tool-setting jig and the transfer arm.

It will also be appreciated that although various dial gauges have beenillustrated and described, it would be possible to use vernier gaugesinstead.

In a modification, the screw and location pegs 90 used to set thetoolholders on the cross-slide jig are replaced by plain cylindricalpegs and the holes 88 are not screw threaded, so that the location pegscan be slid up to their reference surfaces 85 and 87. Screws extendlongitudinally into the toolholders to engage with and lock the locationpegs when these have been set. This modification provides more accuratesetting because it reduces errors due to the feel of a screw setting,and also it is more rapid than the screw setting.

Although the present invention has been described above to a somewhatdetailed extent, the invention is not limited to any particularconstruction, and it is my intention to cover hereby all adaptations,modifications, and changes thereof which come within the practice ofthose skilled in the art to which the invention relates and within thescope and spirit of the appended claims.

Having described my invention, 1 claim:

1. Apparatus for presetting tools for use in a machine tool having frontand rear cross slides having a support for a toolholder thereon and toollocating means thereon, said apparatus including a jig for presettingtools relative to a cross slide toolholder prior to positioning saidtools and cross slide toolholder on the cross slides, said jig beingoperable in presetting tools for use on both the front and rear crossslides and including a base having a surface representing a tool heightreference plane, a pair of members extending outwardly from said base,one of said members having a surface comprising a tool length referenceplane for presetting tools to be used on the front cross slide and theother of said members having a surface comprising a tool lengthreference plane for presetting tools to be used on the rear cross slide,means extending transversely to said members and said base and having asurface comprising a tool radius reference plane, and means located onsaid base between said members for supporting a toolholder thereon andbeing a replica of the support for the toolholder on said cross slideswhereby said jig allows presetting of said tools for length of cut,radius of cut, and height with respect to said cross slide toolholder,and wherein the preset position of said tools can be measuredsimultaneously with respect to length of cut, radius of cut and heightrelative to said cross slide toolholder.

2. Apparatus for presetting tools for use in a machine tool, havingfront and rear cross slides with tool locating means thereon and aturret having a tool locating datum surface, said apparatus comprising adatum surface transfer means adaptable to lie on the datum surface andbeing operable to extend adjacent the tool locating means on the crossslide, a jig for presetting tools relative to a cross slide toolholderprior to positioning said tools and cross slide toolholder on the crossslides, said jig being operable to preset tools for use in both thefront and rear cross slides and including a base having a surfacecomprising a tool height reference plane, a pair of pivotal side platesextending outwardly from said base, one of said side plates having asurface comprising a tool length reference plane for presetting tools tobe used on the front cross slide and the other of said side plateshaving a surface comprising a tool length reference plane for presettingtools to be used on the rear cross slide, a rear wall extendingtransversely of said side plates and said bed and having a surfacecomprising a tool radius reference plane, and said cross slidetoolholder having a surface engaged by the tool locating means on thecross slide to position the toolholder on the cross slide.

3. Apparatus for presetting tools for use in a machine tool as describedin claim 2 wherein the datum surface transfer means comprises a transferarm and further including means for mounting the transfer arm on theturret.

4. Apparatus as defined in claim 2 further including an invertibleheight detector operable in setting the height of said tools relative tosaid cross slide toolholder to be used on the front cross slide whensaid height detector is in an upright position and the height of saidtools to be used on the rear cross slide when said height detector is inan inverted position.

1. Apparatus for presetting tools for use in a machine tool having frontand rear cross slides having a support for a toolholder thereon and toollocating means thereon, said apparatus including a jig for presettingtools relative to a cross slide toolholder prior to positioning saidtools and cross slide toolholder on the cross slides, said jig beingoperable in presetting tools for use on both the front and rear crossslides and including a base havinG a surface representing a tool heightreference plane, a pair of members extending outwardly from said base,one of said members having a surface comprising a tool length referenceplane for presetting tools to be used on the front cross slide and theother of said members having a surface comprising a tool lengthreference plane for presetting tools to be used on the rear cross slide,means extending transversely to said members and said base and having asurface comprising a tool radius reference plane, and means located onsaid base between said members for supporting a toolholder thereon andbeing a replica of the support for the toolholder on said cross slideswhereby said jig allows presetting of said tools for length of cut,radius of cut, and height with respect to said cross slide toolholder,and wherein the preset position of said tools can be measuredsimultaneously with respect to length of cut, radius of cut and heightrelative to said cross slide toolholder.
 2. Apparatus for presettingtools for use in a machine tool, having front and rear cross slides withtool locating means thereon and a turret having a tool locating datumsurface, said apparatus comprising a datum surface transfer meansadaptable to lie on the datum surface and being operable to extendadjacent the tool locating means on the cross slide, a jig forpresetting tools relative to a cross slide toolholder prior topositioning said tools and cross slide toolholder on the cross slides,said jig being operable to preset tools for use in both the front andrear cross slides and including a base having a surface comprising atool height reference plane, a pair of pivotal side plates extendingoutwardly from said base, one of said side plates having a surfacecomprising a tool length reference plane for presetting tools to be usedon the front cross slide and the other of said side plates having asurface comprising a tool length reference plane for presetting tools tobe used on the rear cross slide, a rear wall extending transversely ofsaid side plates and said bed and having a surface comprising a toolradius reference plane, and said cross slide toolholder having a surfaceengaged by the tool locating means on the cross slide to position thetoolholder on the cross slide.
 3. Apparatus for presetting tools for usein a machine tool as described in claim 2 wherein the datum surfacetransfer means comprises a transfer arm and further including means formounting the transfer arm on the turret.
 4. Apparatus as defined inclaim 2 further including an invertible height detector operable insetting the height of said tools relative to said cross slide toolholderto be used on the front cross slide when said height detector is in anupright position and the height of said tools to be used on the rearcross slide when said height detector is in an inverted position.